Rupert Murdoch’s British Sky Broadcasting (BSkyB) is in the midst of a legal battle with Skype over ownership of the “Sky” portion that both companies share in their names.

Skype filed for an Initial Public Offering earlier this week, and the legal challenge from BSkyB was discussed in the filing.

BSkyB is disputing Skype’s application for trademark of the brand and bubble logo in the European Union and several other countries including India, Norway and Brazil.

BSkyB is a satellite broadcaster, Internet service and telephony service provider, which means the two companies operate within the same field and could, thus, be seen as competitors with similar names. BSkyB is vying for the trademark with the assertion that the likeness in names could confuse consumers.

Though Skype has contested the challenge successfully in Brazil and Turkey, permission to use the name was denied by the EU trademark registry (OHIM).

Skype said in the filing that they intend to appeal the decision, first, in the OHIM Board of Appeal, and, second, if necessary, to the Court of Justice of the European Community.

If BSkyB’s challenge proves to be successful Skype could be barred from trading in its own name within the EU.

The Skype filing also mentioned, “If these oppositions to our application for trademark registration are ultimately successful, it will be more difficult for us to prevent third parties from using the Skype brand without our permission, which may have a material adverse effect on our business.”

Additionally, a successful challenge in the EU could be a harbinger for more trademark infringement suits in other countries and regions, both from BSkyB and other similarly-named parties.